ARM: 6641/1: ep93xx: implement gpiolib set_debounce for built-in GPIOs

GPIO Ports A, B, and F on the ep93xx provide interrupt capability.  It
is possible to debounce the input signal on these ports when interrupts
are enabled.

Support for this debounce capability was provided with an ep93xx internal
function.  Now that gpiolib knows about gpio debounce, use the gpiolib
method and do not export the internal function.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-ep93xx/gpio.c b/arch/arm/mach-ep93xx/gpio.c
index bec34b8..a889fa7 100644
--- a/arch/arm/mach-ep93xx/gpio.c
+++ b/arch/arm/mach-ep93xx/gpio.c
@@ -61,7 +61,7 @@
 	gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
 }
 
-void ep93xx_gpio_int_debounce(unsigned int irq, int enable)
+static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
 {
 	int line = irq_to_gpio(irq);
 	int port = line >> 3;
@@ -75,7 +75,6 @@
 	__raw_writeb(gpio_int_debounce[port],
 		EP93XX_GPIO_REG(int_debounce_register_offset[port]));
 }
-EXPORT_SYMBOL(ep93xx_gpio_int_debounce);
 
 static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
 {
@@ -335,6 +334,20 @@
 	local_irq_restore(flags);
 }
 
+static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
+				    unsigned offset, unsigned debounce)
+{
+	int gpio = chip->base + offset;
+	int irq = gpio_to_irq(gpio);
+
+	if (irq < 0)
+		return -EINVAL;
+
+	ep93xx_gpio_int_debounce(irq, debounce ? true : false);
+
+	return 0;
+}
+
 static void ep93xx_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 {
 	struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
@@ -434,6 +447,18 @@
 				 EP93XX_SYSCON_DEVCFG_GONIDE |
 				 EP93XX_SYSCON_DEVCFG_HONIDE);
 
-	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++)
-		gpiochip_add(&ep93xx_gpio_banks[i].chip);
+	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
+		struct gpio_chip *chip = &ep93xx_gpio_banks[i].chip;
+
+		/*
+		 * Ports A, B, and F support input debouncing when
+		 * used as interrupts.
+		 */
+		if (!strcmp(chip->label, "A") ||
+		    !strcmp(chip->label, "B") ||
+		    !strcmp(chip->label, "F"))
+			chip->set_debounce = ep93xx_gpio_set_debounce;
+
+		gpiochip_add(chip);
+	}
 }